Track-type machines are used in a wide variety of rugged service environments. The use of ground engaging tracks rather than wheels can provide enhanced traction, stability, and robustness to a machine system over what might otherwise be available. Mining, construction, landfills, forestry, and still other service environments are notable examples of where track-type machines are advantageously used. A typical undercarriage system in a track-type machine includes a plurality of track shoes coupled together in an endless track chain by way of a set of track links, and extending about a drive sprocket and one or more rotatable idlers. Many undercarriage system components experience metal-on-metal wear during service. In addition, abrasive materials are present at most worksites where track-type machines are used. The metal-on-metal contact between and among undercarriage system components, exacerbated by abrasive materials, can subject undercarriage systems to substantial wear.
Rotation of the one or more drive sprockets and idler against components of the track such as the track links and/or track shoes, and particularly where abrasive materials intrude between the drive sprocket or idler and the track, can wear away material such that dimensions, contact patterns, and other geometric properties of the subject components tend to change over time. Many undercarriage systems include mechanisms adapted to compensate for wear and the resulting geometric changes. Various types of idler recoil systems are used in track-type machines at least in part to maintain a tensioned state of the track, while allowing chunks of debris such as rocks and the like to occasionally pass between the rotating idler and the track links or track shoes. Such idler recoil systems may inherently, or by way of manual adjustments, compensate for the wear induced geometric changes mentioned above. For instance, over time an outer surface of a rotatable idler can lose material such that a diameter of the idler is reduced. Where equipped with an idler recoil system, an actuator or other compensating mechanism can “push” the idler against the track such that a suitable tensioned state of the track is maintained despite a reduction in idler diameter or other wear induced geometric changes.
Although the use of idler recoil systems and the like can extend track service life over what might otherwise be possible, eventually wear on the idler and/or other undercarriage system components necessitates track servicing or rebuild if efficient use of the machine, and in some cases any use, is to continue. For reasons which will be readily apparent, it is desirable upon rebuild or servicing to reuse at least some of the undercarriage system components rather than purchasing all new parts. To this end, rotatable idlers which have been subjected to field service wear may sometimes be repaired and/or remanufactured. One technique for returning a worn idler to a condition suitable for returning to service involves adding material to an outer surface of the worn idler to return the idler to a size and/or shape similar to that of a new idler. Repair technicians may perform a very labor intensive process known in the art as “hard facing” in which numerous layers of material are deposited one upon the other on the outer surface of the idler. While in many instances a hard facing process can be economically superior over purchasing a new idler, idlers repaired in this manner may have reduced robustness and greater susceptibility to certain types of wear than a new idler, and suffer from other shortcomings.